Exploring titanium(IV) chemical proximity to iron(III) to elucidate a function for Ti(IV) in the human body.

•Ti(IV) similarity to Fe(III) hints towards its function and storage in humans.•Ti(IV) can inhibit intracellular Fe bioavailability and function.•Properties of in vitro ligands of Ti important in identifying in vivo ligands.•Redox, structural, growth, and antibacterial functions proposed for Ti.•Better tools are needed to decipher the in vivo fate of Ti(IV)